PHP，SOAPClient：找不到调度方法

This is my WSDL XML: (Generated with SoapUI)

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ser="http://soap.test.com/">
   <soapenv:Header/>
   <soapenv:Body>
      <ser:myMethod>
         <user>
            <id>?</id>
            <name>?</name>
         </user>
         <code>?</code>
      </ser:myMethod>
   </soapenv:Body>
</soapenv:Envelope>

And my PHP code to consume the "myMethod" method:

$opts = array(
     'location' => 'http://example.com/myServices?WSDL',
     'uri'      => 'http://soap.test.com'
);

$client = new SOAPClient(null, $opts);

$res = $client->__soapCall('myMethod', array(
    "id" => "123",
    "name" => "Sam"
));

var_dump($res);

And I get the Cannot find dispatch method for {http://soap.test.com} myMethod error.

I've tested the SOAP with SoupUI and it has responsed correctly.

What is wrong here?